Bayern had reached an agreement over a new contract with Sane, but the player changed agents before signing it and has since demanded an improved offer. With his deal expiring at the end of June, he could leave for free amid interest from Arsenal as well as Turkish clubs Galatasaray and Fenerbahce. However, Hamann feels the German giants have lost some control over the situation and called for a show of strength.

Ex-Bayern, Liverpool and Germany star Hamann said: “Bayern really need to be careful not to lose face in the negotiations with Sane. I don’t understand why Bayern President Herbert Hainer, on the one hand, publicly speaks out against an improved offer on this issue. But on the other hand, a new offer is now on the table.”

Hamann urged Bayern management to take a stance by saying: “I can’t take that player to the Club World Cup. It’s time for Bayern’s management to show strength and backbone and take a unified stance.

“The Sane case shows once again that FC Bayern really needs to be careful. The club mustn’t let the agents and players take over control. I see this as a very dangerous development at Sabener Strasse that shouldn’t be underestimated. ”